The invention relates to an electromechanical transducer for musical instruments and more particularly to an electromagnetic pickup for a guitar.
Electricomagnetic transducers are used on electrical musical instruments to neutralize the effects if currents induced by adjacent electrical devices and for converting the vibrations created, when the strings of the instrument are played, into an electrical output wherein the sounds are amplified.
Conventional electrical pickups are prone to humming noises in attached amplification devices due to currents created by adjacent electrical devices that are transferred to the guitar pickup. A common way of counteracting the hum and amplifying the sound of the guitar is to wind the pickups with two different gauges the same number of turns on each coil. The dual winds allow greater flexibility of tonal shaping or tuning of each coil. Likewise, when used on a single coil, non-hum cancelling device, initial winds can be connected in series to secondary winds to produce a sound with a pronounced increase in volume DC resistance similar to the output of a dual coil device. By using an external switching device, connection between the initial and secondary winds can be tapped and either set of winds can be shunted to ground. Thus, the second tone and output parameters can be achieved that are closer to that of normal, single cole type devices.
The current state of the prior art provides pickups using a single gauge wire and tap that is drawn to ground, and with a secondary lead is attached to the coil wire at a pre-determined point in the number of turns in the wire, thereby allowing a signal from turns of wire up to that connection to be sensed in the circuit.
While the desired frequency response may have been achieved in these configurations, the output or DC resistance is diminished due to fewer number of turns of wire being sensed in the circuit.
A solution to the problem of reduced DC resistance is to increase the amplitude of the device. This is accomplished by using more magnets to produce much greater flux in the device. However, due to the proximity of the magnets with the steel core strings, the vibration of the strings is dampened by the increase in magnetic flux necessary to achieve desired volume when the coil of wire is tapped at a predetermined point.
Using a dual wind pickup will resolve the dampening problem by allowing a sufficient number of initial turns to reproduce desired single coil tonality, yet not diminish the output due to use of different gauge wire without the addition or larger magnets. When secondary turns of different gauge wire are added, the sum of both the number of turns yields a much greater signal.
An object of the present invention is to provide a musical instrument transducer that allows flexibility in tonal shaping or tuning of each wire coil.
Another object of the present invention is to provide a musical instrument pickup that is dual wind using two different gauges of wire.
The various objects of the present invention are realized with a musical instrument pickup having a plurality of turns of a given gauge wire on a bobbin or coilform. Each end of each wire is terminated on a metal terminal strip attached to the bobbin or coilform. A second plurality of turns of a different gauge wire are wound on top of the initial turns of the wire. When the secondary turns of wire are completed, both ends of the wire are terminated on individual terminal strips attached to the bobbin or coilform. The coils wound in this manner may be used individually or two or more coils may be connected in series to form a hum cancelling device.
The bobbin or coilform can have a wire attached to each terminal thereby allowing the signal of each individual set of winds to be sensed either as a series connection wherein both the initial and secondary winds are sensed together, or individually wherein either of the winds may be connected to a circuit or switching device thereby enabling initial turns, secondary turns, or both to be sensed. For example, the initial winds of two adjacent coils only may be sensed or secondary (outside winds) may be sensed only. The desired frequency response can be controlled based on the side of the gauge of wire used in the initial and secondary winds.
The present pickup achieves the objectives set forth by having a central core bobbin or coilform with a first winding wound around the central core of the bobbin, and a second winding wound around the first winding. Both ends of each winding are attached to a respective termination point. Each termination point is connected to an amplification source wherein the tones of the instrument strings are amplified.